JP2009165947A - Ultrasonic washing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic washing device which is capable of conducting the stable washing without enlarging the source capacity and without stopping the washing of a material to be washed. <P>SOLUTION: In the ultrasonic washing device 1 having a function to sweep the driving frequency of a vibrator 5, excessive electric current flows if the sweep frequency exceeds a certain value. Therefore, the sweep width is controlled by DSP 21 so that the excessive electric current does not flow more than a particular value by detecting the electric current value supplied to the vibrator 5. When the driving frequency is swept, the soft start to gradually increase electric power is conducted so that energy is not rapidly imparted to the vibrator 5. The tracking control of its resonant frequency is conducted for each constant hour using DSP 21 because the resonant frequency is changed in accordance with the position, volume of the material to be washed and environment such as the temperature of the washing liquid and the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultrasonic cleaning apparatus that cleans an object to be cleaned in a cleaning liquid using ultrasonic waves generated from a vibrator.

Conventionally, an ultrasonic cleaning apparatus is used for cleaning electronic components, printed boards, and the like. FIG. 1 is a waveform diagram of signals supplied to the vibrator during single operation and sweep operation. In the conventional ultrasonic cleaning apparatus, as shown in FIG. 1 (A), an operation of cleaning with the driving frequency of the vibrator fixed (referred to as single operation), as shown in FIG. 1 (B), There is one that performs frequency modulation operation (referred to as sweep operation) in which the drive frequency of the vibrator is fluctuated at a constant period (see, for example, Patent Document 1).
JP 2006-314872 A

  In an ultrasonic cleaning device, if the temperature of the cleaning liquid changes or the amount of the object to be cleaned changes while cleaning the object to be cleaned, the resonance frequency of the vibrator changes, and the current (electric power) flowing through the vibrator changes accordingly. ) Will change. In the ultrasonic cleaning apparatus, the resonance frequency of the vibrator changes depending on the reflection from the facing surface of the cleaning tank and the type of cleaning liquid, and the current (electric power) flowing through the vibrator changes accordingly. For this reason, the conventional ultrasonic cleaning apparatus has the following problems.

  FIG. 2 is a graph showing the measurement results of the relationship between the resonance frequency of the vibrator and the current flowing through the vibrator. FIG. 2 shows cases where the power setting values of the ultrasonic cleaning apparatus are 20%, 25%, 30%, and 35%. When the center value of the resonance frequency of the vibrator is set to 25 kHz during the sweep operation, the current flowing through the vibrator becomes the minimum value at the center frequency from FIG. 2 and flows to the vibrator as the frequency is changed from the center frequency. It can be seen that the current changes parabolically. Moreover, it turns out that the inclination of a parabola becomes large, so that an electric power setting value is enlarged. Furthermore, it can be seen that when the difference between the frequency of the signal supplied to the vibrator and the center frequency exceeds a certain value, the current flowing through the vibrator changes in a shape different from a parabolic shape.

  The resonance frequency-current characteristics of the vibrator are as described above. In the conventional ultrasonic cleaning apparatus, when the resonance frequency of the vibrator changes due to temperature change of the cleaning liquid, the center frequency of the signal supplied to the vibrator during sweep operation is Although the frequency is changed, since the fluctuation range (sweep width) of the signal frequency is constant, the maximum value of the current in one cycle of the sweep is increased. For this reason, current exceeding the preset current limit flows during startup and operation of the ultrasonic cleaning device, causing the ultrasonic cleaning device to stop while the workpiece is being cleaned, or the vibrator to fail. Sometimes happened. Further, in the conventional ultrasonic cleaning apparatus, in order to prevent the ultrasonic cleaning apparatus from stopping during the cleaning of the object to be cleaned, the current limit value can be increased unless the power supply capacity is increased very much. There wasn't.

  Accordingly, an object of the present invention is to provide an ultrasonic cleaning apparatus capable of performing stable cleaning without increasing the power supply capacity and without stopping the cleaning of an object to be cleaned.

(1) an ultrasonic generating means installed in a cleaning tank for storing a cleaning liquid, and ultrasonically vibrating and applying the vibration to the cleaning liquid;
Signal generating means for supplying a high frequency signal for ultrasonically vibrating the ultrasonic generating means;
Current / voltage detection means for detecting the current and voltage of the ultrasonic wave generation means;
Storage means for storing a current limit value at the time of a sweep process for regularly changing the frequency of the high-frequency signal supplied to the ultrasonic wave generation means by the signal generation means;
Operation means for receiving an operation of setting a power setting value of the high-frequency signal to a fixed value;
When the operation means accepts an operation to set the power setting value to a fixed value, the maximum current value detected by the current / voltage detection means during the sweep process and the current limit read from the storage means A control means for comparing the value and changing the frequency of the high-frequency signal that the signal generation means supplies to the ultrasonic wave generation means according to the result,
It is provided with.

  In an ultrasonic cleaning device, if the temperature of the cleaning liquid changes or the position or amount of the object to be cleaned changes while cleaning the object to be cleaned, the resonance frequency of the ultrasonic generator changes, and this causes the generation of ultrasonic waves. The current flowing through the means changes. Further, in the ultrasonic cleaning apparatus, the resonance frequency of the ultrasonic generating means changes depending on the reflection from the facing surface of the cleaning tank and the type of cleaning liquid, and the current flowing through the ultrasonic generating means changes accordingly. In the ultrasonic cleaning apparatus, as described above, the cleaning operation is stopped when the current flowing through the ultrasonic wave generator changes and exceeds the current limit value. In this configuration, when the power setting value is fixed during the sweep process, the ultrasonic cleaning device changes the frequency of the high-frequency signal supplied to the ultrasonic wave generation unit based on the current detected by the current / voltage detection unit. Thus, the maximum value of the current flowing through the ultrasonic wave generating means is made equal to or less than the current limit value. Therefore, even if conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, the current flowing through the ultrasonic generator does not exceed the limit current value, as in the conventional ultrasonic cleaning apparatus. It is possible to prevent the cleaning operation from stopping.

(2) an ultrasonic wave generating means installed in a cleaning tank for storing a cleaning liquid, and ultrasonically vibrating the vibration liquid to the cleaning liquid;
Signal generating means for supplying a high frequency signal for ultrasonically vibrating the ultrasonic generating means;
Current / voltage detection means for detecting the current and voltage of the ultrasonic wave generation means;
Stores the upper limit value of the power setting value for the sweep width, which is the change width of the frequency of the high-frequency signal, during the sweep process in which the signal generation means regularly changes the frequency of the high-frequency signal supplied to the ultrasonic wave generation means. Storage means;
Operation means for accepting an operation for setting the sweep width to a fixed value;
When the operation means accepts an operation to set the sweep width to a fixed value, the maximum value of the power calculated from the current and voltage detected by the current / voltage detection means and the setting read from the storage means during the sweep process A control unit that compares the power setting value with respect to the sweep width, and changes the power setting value of the high-frequency signal that the signal generation unit supplies to the ultrasonic wave generation unit according to the result.
It is provided with.

  In the ultrasonic cleaning device, when the temperature of the cleaning liquid changes or the amount of the cleaning object changes while cleaning the object to be cleaned, the resonance frequency of the ultrasonic generating means changes, and accordingly, the ultrasonic generating means The flowing current changes. Further, in the ultrasonic cleaning apparatus, the drive frequency of the ultrasonic generator changes depending on the reflection from the face of the cleaning tank and the type of cleaning liquid, and the current flowing through the ultrasonic generator changes accordingly. Therefore, the power of the high frequency signal supplied to the ultrasonic wave generating means changes. In the ultrasonic cleaning apparatus, when the power changes as described above and exceeds the power set value, the cleaning operation is stopped. In this configuration, when the sweep width is fixed, the ultrasonic cleaning device calculates the power value from the current and voltage detected by the current / voltage detection means, and based on this power value, the ultrasonic generation means The power setting value of the high-frequency signal to be supplied is changed so that it is not more than the upper limit value of the power setting value for the sweep width. Therefore, even when conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, the power of the high-frequency signal supplied to the ultrasonic wave generator does not exceed the power setting value, and the cleaning operation stops. Can be prevented.

  (3) At the start of the sweep process, the control unit sets a sweep width, which is a frequency width that regularly changes the frequency of the high-frequency signal, to a minimum value, and sets the sweep width to the set value of the sweep width. It is characterized by increasing by a certain amount.

  At the start of the sweep process, the resonance frequency of the ultrasonic generator changes depending on conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned, and the current flowing to the ultrasonic generator and the power of the ultrasonic generator change, When the sweep process is started with the sweep width set, the cleaning operation may stop because the current flowing through the ultrasonic wave generation unit exceeds the limit value or the power exceeds the set value. In this configuration, at the start of the sweep process, the sweep width is increased by a certain amount from the minimum value to the set value of the sweep width. Therefore, at the start of the sweep process, the current flowing through the ultrasonic generator does not exceed the limit current value, and the power supplied to the ultrasonic generator does not exceed the power setting value. Can be prevented.

  (4) Before the start of the sweep process, the control means changes the frequency of the high-frequency signal supplied from the signal generation means to the ultrasonic wave generation means by a certain amount, and is detected by the current / voltage detection means. The frequency at which the current value becomes the minimum value is detected, and the sweep process is characterized in that the frequency of the high-frequency signal is regularly changed with this frequency as a center frequency.

  At the start of the sweep process, the sweep width starts when the resonance frequency of the ultrasonic generator changes due to conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned and the current flowing through the ultrasonic generator changes. Since the center of the nozzle is deviated, there is a possibility that the cleaning operation may stop because the current flowing through the ultrasonic generator exceeds the limit current value or the power supplied to the ultrasonic generator exceeds the power setting value. . In this configuration, the ultrasonic cleaning device detects the frequency at which the value of the current flowing through the ultrasonic wave generating means becomes the minimum value before the start of the sweep process, and performs the sweep process using this frequency as the center frequency. Therefore, even if the resonance frequency of the ultrasonic generator changes depending on conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned, and the current flowing through the ultrasonic generator changes, the center frequency is set to the minimum value before the sweep process starts. Therefore, the current that flows to the ultrasonic generator during the sweep process does not exceed the limit current value, and the power supplied to the ultrasonic generator does not exceed the power setting value. Can be prevented.

  (5) The control means interrupts the sweep process every time the sweep process is performed for a certain period of time, and changes the frequency of the high-frequency signal supplied from the signal generation means to the ultrasonic wave generation means. The frequency at which the current value detected by the current / voltage detection means is minimum is detected, the frequency is reset to the center frequency, and the sweep process is restarted.

  In this configuration, the ultrasonic cleaning device changes the frequency of the high-frequency signal supplied to the ultrasonic generator based on the current detected by the current / voltage detector and minimizes the current flowing through the ultrasonic generator. Control. Therefore, even if conditions such as the temperature of the cleaning solution and the amount of the object to be cleaned change during the sweep process, the center frequency of the sweep process is reset to the frequency at which the current flowing through the ultrasonic generator is minimized. The current flowing through the generating means does not exceed the limit current value, and the power supplied to the ultrasonic generating means does not exceed the power set value, so that the cleaning operation can be prevented from stopping.

  According to the present invention, even when conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, the current flowing through the ultrasonic generator exceeds the limit current value or is supplied to the ultrasonic generator. The power of the high-frequency signal does not exceed the power setting value, and it is possible to prevent the cleaning operation from stopping as in the conventional ultrasonic cleaning apparatus.

  FIG. 3 is a block diagram showing a schematic configuration of the ultrasonic cleaning apparatus according to the embodiment of the present invention. As shown in FIG. 3, the ultrasonic cleaning apparatus 1 includes an oscillator 3 and a vibrator 5. The oscillator 3 includes a full-wave rectifier circuit 11, a smoothing capacitor 13, an inverter circuit 15, a matching circuit 17, a V / I detection circuit 19, a DSP module (hereinafter referred to as DSP) 21, a storage unit 23, a display unit 25, and An operation unit 27 is provided. The vibrator 5 is installed at the bottom of the cleaning tank 41 in which the cleaning liquid 43 is stored (stored), and is connected to the matching circuit 17 of the oscillator 3.

  The full wave rectifier circuit 11 rectifies the AC voltage supplied from the AC power supply 31.

  The smoothing capacitor 13 smoothes the voltage rectified by the full-wave rectifier circuit 11.

  The inverter circuit 15 switches the switching timing according to the control signal output from the DSP module 21 and converts the DC voltage into a high-frequency AC voltage.

  The matching circuit 17 includes a transformer T, a coil Lm, which is a matching impedance element, and a capacitor Cm. The matching circuit 17 is connected between the inverter circuit 15 and the vibrator 5 via the transformer T to match the impedances of the two. A signal from the transformer T is supplied to the vibrator 5.

  The vibrator 5 vibrates according to a signal (high frequency signal) supplied from the matching circuit 17 and generates an ultrasonic wave. The cleaning liquid 43 is vibrated by the ultrasonic wave generated by the vibrator 5 and cleans an object to be cleaned (not shown).

  The V · I detection circuit 19 detects the current and voltage of the signal supplied from the matching circuit 17 to the vibrator 5. The V · I detection circuit 19 detects the phase difference between the current and voltage of the signal supplied from the matching circuit 17 to the vibrator 5.

  The DSP 21 outputs a control signal for performing switching control to a switching element (not shown) of the inverter circuit 15 based on the current and voltage detected by the V · I detection circuit 19. The DSP 21 performs constant power control based on the current and voltage of the signal supplied from the matching circuit 17 to the vibrator 5 and the phase difference between the current and the voltage detected by the V / I detection circuit 19.

  The storage unit 23 stores data such as a sweep current limit value and a power setting value for the sweep width.

  The display unit 25 displays items to be transmitted to the user, such as the state of the ultrasonic cleaning device 1.

  The operation unit 27 includes a plurality of switches and receives user operations.

  The ultrasonic cleaning apparatus 1 is configured as described above, and the user operates the ultrasonic cleaning apparatus 1 and puts (submerges) the object to be cleaned into the cleaning liquid 43 of the cleaning tank 41, so that the object to be cleaned is Can be washed.

  Next, the operation of the ultrasonic cleaning apparatus 1 will be described. The ultrasonic cleaning device 1 operates in one of three modes: a soft start mode, a tracking mode, and a sweep mode. FIG. 4 is a diagram showing the relationship between the modes of the ultrasonic cleaning apparatus and a time chart showing the operation in the soft start mode.

  The ultrasonic cleaning apparatus 1 performs a single operation in which the frequency of the signal supplied to the vibrator is not changed according to a user setting, or a sweep operation in which the frequency of the signal supplied to the vibrator is changed at a constant period. Although detailed description is omitted, it is possible to perform a shot operation in which the vibrator is vibrated intermittently in order to deaerate the air in the cleaning tank.

  As shown in FIG. 4A, at the time of single operation, the ultrasonic cleaning device 1 switches the mode in the order of the soft start mode and the tracking mode.

  During the sweep operation, the ultrasonic cleaning device 1 switches the mode in the order of the soft start mode, the tracking mode, and the sweep mode. In addition, when the sweep mode is performed for a certain period of time, the ultrasonic cleaning apparatus 1 switches to the tracking mode and performs the sweep mode again when a set time (for example, 1 second) elapses.

  Moreover, the ultrasonic cleaning apparatus 1 switches to the soft start mode when the power setting value is changed by the user in the tracking mode and the sweep mode. When the soft start mode is completed, the mode is switched to the tracking mode or the sweep mode.

1. Soft start mode In this mode, the power setting value (output setting value) is gradually increased when the ultrasonic cleaning apparatus 1 is started or when the power setting is changed. By performing this mode, it is possible to prevent the apparatus from being suddenly stopped at the time of activation as in the conventional case, and the apparatus can be operated reliably.

  The adjustment range of the power setting value of the ultrasonic cleaning device 1 is 25% to 100% as an example. FIG. 4B shows a case where the user sets the power setting value to 35%.

  When the DSP 21 of the ultrasonic cleaning apparatus 1 detects that the operation instruction has been received by the operation unit 27, the DSP 21 first sets the power setting value to 25% which is the minimum value of the adjustment range. Then, after the control waiting time (50 ms in the figure) elapses, the tracking control is performed for a fixed time (150 ms in the figure). Here, since the current is unstable immediately after the power setting value is changed, the control waiting time is set as the time until the current is stabilized in the soft start mode. The tracking control is control for changing the frequency of a signal supplied to the vibrator 5 little by little to minimize the current flowing through the vibrator 5.

  As described with reference to FIG. 2, the frequency-current characteristic of the vibrator 5 is parabolic, and it has been experimentally found that the value near the default frequency (hereinafter referred to as the initial value) becomes the minimum value. Yes. Therefore, in tracking control in the soft start mode, first, the frequency of the signal supplied to the vibrator 5 is set to an initial value (for example, 25 kHz), and the current value when the frequency of the signal is increased by 0.1 kHz (for example, 25.1 kHz) The current value when the signal frequency is lowered by 0.1 kHz (for example, 24.9 kHz) is compared, and the frequency is changed according to the difference between the two current values. That is, when the difference between the two current values is 0, the frequency is set to the initial value without being changed. Further, the frequency is increased or decreased depending on whether the difference between the two current values is a positive number or a negative number. Further, the smaller the difference is, the smaller the frequency change amount is, and the larger the difference is, the larger the frequency change amount is. When this process is performed, one or a plurality of threshold values are set in advance, and the difference value between the two current values is compared with the threshold value.

  When the signal frequency is changed, the current value when the signal frequency is subsequently increased by 0.1 kHz is compared with the current value when the signal frequency is decreased by 0.1 kHz, and according to the difference value as described above. Change the frequency. Such processing is repeated to minimize the signal current supplied to the vibrator 5.

  In the tracking control, when a set time (for example, 150 ms) elapses before obtaining the minimum current value, this process is stopped at that time, and the current value obtained at that time is set to the minimum value.

  When the obtained current value (minimum value) is less than the preset limit current value, the power setting value is increased by 5% and the same processing is performed.

  On the other hand, if the current value of the vibrator 5 is greater than or equal to the limit current value during tracking control, the DSP 21 displays an error message on the display unit 25 according to the user setting, and sets the power to the user. The power setting value is set to the maximum value at which the current value of the vibrator 5 is less than the limit current value without prompting the value to be changed or causing the display unit 25 to display no error.

2. Tracking mode In this mode, the current flowing through the vibrator is monitored, and the tracking control described above is always performed so that the current becomes a minimum value. By performing this mode, the current flowing through the vibrator does not exceed the limit current value, and the stop of the cleaning operation can be prevented. Further, during the sweep operation, the frequency of the vibrator can be adjusted to an optimum resonance frequency.

  In single operation, after the soft start is completed, the current flowing through the vibrator is constantly monitored, and tracking control is always performed so that this current becomes the minimum value.

  During the sweep operation, the tracking mode is set for a set time (for example, 1 second) before the soft start mode is completed and the sweep mode is started, and every time the sweep mode is performed for a certain time (for example, 10 minutes). 5 is adjusted to the center frequency at which the current flowing in the circuit 5 becomes the minimum value.

  Note that the ultrasonic cleaning device 1 shifts to the soft start mode when the change of the power setting value is received during the tracking mode.

3. Sweep mode In this mode, as shown in FIG. 1B, control is performed to vary the frequency of a signal supplied to the vibrator at a constant period.

  The user can select either the sweep width priority process or the power setting priority process when setting the sweep mode. Further, the ultrasonic cleaning apparatus 1 performs the sweep width soft start process at the start of the sweep mode regardless of which one of the sweep width priority process and the power setting priority process is selected.

  FIG. 5 is a graph showing the relationship between the sweep period and the sweep width, a graph showing the relationship between the sweep width and the power setting value, and a graph showing the relationship between the frequency of the high-frequency signal supplied to the vibrator and the current.

  As shown in the graph shown in FIG. 5A, the ultrasonic cleaning apparatus 1 can set the sweep period and the sweep width. For example, the sweep period can be set in the range of 5 ms to 50 ms, and the sweep width can be set in the range of 0.5 kHz to 3.5 kHz.

  In the ultrasonic cleaning apparatus 1, as shown in FIG. 5B, the relationship between the sweep width and the power set value (output set value) is set, the sweep width priority process is selected, and the sweep width is, for example, 2.0 kHz. Is set, the sweep width is increased by 0.1 kHz up to 2.0 kHz by the sweep width soft start process.

a. Sweep Width Soft Start Process The DSP 21 of the ultrasonic cleaning apparatus 1 starts the sweep mode following the soft start mode and the tracking mode. At the start of the sweep mode, the sweep width soft start process is performed as described above. The sweep width soft start process is a process of increasing the sweep width by a certain amount (for example, by 0.1 kHz) to a set value.

b. Power setting priority processing When the power setting priority processing is set, the ultrasonic cleaning device 1 fixes the power setting value to a value set by the user, and sweeps the frequency of the signal supplied to the vibrator 5 ( Change width). As a result, even if conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, the power of the high-frequency signal supplied to the ultrasonic generator does not exceed the power setting value, and the cleaning operation stops. Can be prevented.

  In the ultrasonic cleaning apparatus 1, when the power setting priority process is selected and the power setting value is set to 65%, for example, the sweep width is increased by 0.1 kHz by the sweep width soft start process. Here, in the graph shown in FIG. 5B, when the power setting value is 65%, the sweep width is 2.0 kHz. As described above, the sweep width depends on various conditions such as the type of the cleaning liquid and the liquid temperature. The upper limit of the width changes. Therefore, in the ultrasonic cleaning device 1, when the power setting priority process is selected, the current and voltage of the signal supplied to the vibrator 5 are monitored, and the constant power control is performed so that the power setting value becomes 65%. While performing, the sweep width as shown in FIG. 5C is increased by 0.1 kHz by the sweep width soft start process, and the sweep width is adjusted so that the power set value does not exceed 65%.

  Next, a process for obtaining an operable sweep width when the power setting priority process is set will be described based on a flowchart. FIG. 6 is a flowchart for explaining the operation of the power setting priority process. In this process, the ultrasonic cleaning apparatus 1 performs constant power control so that the power setting value becomes a value set by the user.

  When starting the sweep mode, the DSP 21 of the ultrasonic cleaning apparatus 1 detects the peak value Is in one sweep cycle and compares this value with a preset limit value Isr of the sweep current (s1). Here, the initial value of the sweep width fd is set to 0, and the increment or decrement a of the sweep width is set to 0.1 kHz.

  When the peak value Is is equal to or less than the limit value Isr (s1: N), the DSP 21 increases the sweep width fd by 0.1 kHz (s2). Then, the sweep width fd is compared with the set value Δf of the sweep width (s3).

  When the sweep width fd is larger than the set value Δf (s3: Y), the DSP 21 sets the sweep width fd to the set value Δf (s4). And the process after step s1 is performed.

  On the other hand, if the sweep width fd is equal to or smaller than the set value Δf in step s3, the process after step s1 is subsequently performed without changing the sweep width fd.

  In step s1, when the peak value Is exceeds the limit value Isr (s1: Y), the sweep width fd is decreased by 0.1 kHz (s5). And the process after step s1 is performed.

c. Sweep width priority processing When the sweep width priority processing is set, the ultrasonic cleaning apparatus 1 fixes the sweep width to a value set by the user and changes the power setting value of the high-frequency signal supplied to the vibrator 5. As a result, even if conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, even if the sweep width of the high-frequency signal supplied to the ultrasonic generator is fixed, the current flowing through the vibrator 5 The current limit value is not exceeded, and the cleaning operation can be prevented from stopping.

  In the ultrasonic cleaning apparatus 1, when the sweep width priority process is selected and the sweep width is set to 2.0 kHz, for example, the sweep width is increased by 0.1 kHz by the sweep width soft start process. Here, in the graph shown in FIG. 5B, when the sweep width is 2.0 kHz, the power setting value is 65%. However, as described above, the power depends on various conditions such as the type of the cleaning liquid and the liquid temperature. The upper limit of the set value changes. Therefore, in the ultrasonic cleaning apparatus 1, when the sweep width priority process is selected, when the sweep width reaches a set value (for example, 2.0 kHz), the power set value is changed to keep the sweep width at the set value. In addition, the ultrasonic cleaning device 1 performs constant power control so that the changed power setting value is obtained.

  Next, a process for obtaining an operable sweep width when the sweep width priority process is set will be described based on a flowchart. FIG. 7 is a flowchart for explaining the operation of the sweep width priority process.

  When the DSP 21 of the ultrasonic cleaning device 1 starts the sweep mode, the DSP 21 detects the peak value Is in one sweep cycle, and compares this value with a preset sweep current limit value Isr (s11). Here, the initial value of the sweep width fd is set to 0, and the increment of the sweep width is set to 0.1 kHz.

  When the peak value Is is equal to or less than the limit value Isr (s11: N), the DSP 21 increases the sweep width fd by 0.1 kHz (s12). Then, the sweep width fd is compared with the set value Δf of the sweep width (s13).

  If the sweep width fd is larger than the set value Δf (s13: Y), the DSP 21 sets the sweep width fd to the set value Δf (s14). And the process after step s21 is performed.

  On the other hand, when the sweep width fd is equal to or smaller than the set value Δf in step s13, the process after step s11 is performed without changing the sweep width fd.

  In step s1, when the peak value Is exceeds the limit value Isr (s11: Y), the sweep width fd is decreased by 0.1 kHz (s15). And the process after step s11 is performed.

  Following the step s14, the DSP 21 detects the peak value Is in one sweep cycle, and compares this value with a preset sweep current limit value Isr (s21). Here, the increment of the power setting value is 0.1 kHz.

  When the peak value Is is equal to or less than the limit value Isr (s21: N), the DSP 21 determines whether or not the power setting value for the set sweep width is exceeded when the power setting value is increased by 1% (s22). ). When the power setting value is increased by 1%, when the power setting value for the set sweep width is exceeded (s22: Y), the power setting value is kept as it is without changing (s23). And the process after step s21 is performed again.

  On the other hand, if the power setting value does not exceed the set sweep width even if the power setting value is increased by 1% (s22: N), the power setting value is increased by 1%. And the process after step s21 is performed again (s24).

  In step s21, when the peak value Is exceeds the limit value Isr (s21: Y), the power set value is decreased by 1% (s25). And the process after step s21 is performed again.

  Note that the ultrasonic cleaning device 1 shifts to the soft start mode when the change of the power setting value is accepted during the sweep mode.

  As described above, in the ultrasonic cleaning apparatus of the present invention, even when the conditions such as the temperature of the cleaning liquid and the amount of the object to be cleaned change during the sweep process, the current flowing through the ultrasonic generating means exceeds the limit current value, The power of the high-frequency signal supplied to the ultrasonic generator does not exceed the power setting value, and it is possible to prevent the cleaning operation from stopping as in the conventional ultrasonic cleaning apparatus.

It is a wave form diagram of the signal supplied to a vibrator at the time of single operation and sweep operation. It is a graph which shows the measurement result of the relationship between the resonant frequency of a vibrator | oscillator, and the electric current which flows into a vibrator | oscillator. It is a block diagram which shows schematic structure of the ultrasonic cleaning apparatus which concerns on embodiment of this invention. It is a figure which shows the relationship of each mode of an ultrasonic cleaning apparatus, and a time chart which shows operation | movement of soft start mode. 4 is a graph showing a relationship between a sweep period and a sweep width, a graph showing a relationship between a sweep width and a power set value, and a graph showing a relationship between a frequency and a current of a high-frequency signal supplied to a vibrator. It is a flowchart for demonstrating operation | movement of a power setting priority process. It is a flowchart for demonstrating operation | movement of a sweep width | variety priority process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic cleaning apparatus 3 ... Oscillator 5 ... Vibrator 11 ... Full wave rectifier circuit 13 ... Smoothing capacitor 15 ... Inverter circuit 17 ... Matching circuit 19 ... V / I detection circuit 21 ... DSP module 23 ... Memory | storage part 25 ... Display part 27 ... Operation part 31 ... AC power supply 41 ... Cleaning tank 43 ... Cleaning liquid

Claims (5)

An ultrasonic wave generating means installed in a cleaning tank for storing a cleaning liquid, and ultrasonically vibrating and applying the vibration to the cleaning liquid;
Signal generating means for supplying a high frequency signal for ultrasonically vibrating the ultrasonic generating means;
Current / voltage detection means for detecting the current and voltage of the ultrasonic wave generation means;
Operation means for receiving an operation of setting a power setting value of the high-frequency signal to a fixed value;
Storage means for storing a current limit value at the time of a sweep process for regularly changing the frequency of the high-frequency signal supplied to the ultrasonic wave generation means by the signal generation means;
When the operation means accepts an operation to set the power setting value to a fixed value, the maximum current value detected by the current / voltage detection means during the sweep process and the current limit read from the storage means A control means for comparing the value and changing the frequency of the high-frequency signal that the signal generation means supplies to the ultrasonic wave generation means according to the result,
An ultrasonic cleaning device. An ultrasonic wave generating means installed in a cleaning tank for storing a cleaning liquid, and ultrasonically vibrating and applying the vibration to the cleaning liquid;
Signal generating means for supplying a high frequency signal for ultrasonically vibrating the ultrasonic generating means;
Current / voltage detection means for detecting the current and voltage of the ultrasonic wave generation means;
Stores the upper limit value of the power setting value for the sweep width, which is the change width of the frequency of the high-frequency signal, during the sweep process in which the signal generation means regularly changes the frequency of the high-frequency signal supplied to the ultrasonic wave generation means. Storage means;
Operation means for accepting an operation for setting the sweep width to a fixed value;
When the operation means accepts an operation to set the sweep width to a fixed value, the maximum value of the power calculated from the current and voltage detected by the current / voltage detection means and the setting read from the storage means during the sweep process A control unit that compares the power setting value with respect to the sweep width, and changes the power setting value of the high-frequency signal that the signal generation unit supplies to the ultrasonic wave generation unit according to the result.
An ultrasonic cleaning device.   The control means sets a sweep width, which is a frequency width that regularly changes the frequency of the high-frequency signal, to a minimum value at the start of the sweep process, and sets the sweep width by a certain amount up to the set value of the sweep width. The ultrasonic cleaning apparatus according to claim 1, wherein the ultrasonic cleaning apparatus is increased.   The control means changes the frequency of the high-frequency signal supplied from the signal generation means to the ultrasonic wave generation means by a predetermined amount before the start of the sweep process, and the current value detected by the current / voltage detection means is changed. The ultrasonic cleaning apparatus according to any one of claims 1 to 3, wherein a frequency having a minimum value is detected, and the frequency of the high-frequency signal is regularly changed with the frequency as a center frequency in the sweep process.   The control means interrupts the sweep process every time the sweep process is performed for a certain period of time, changes the frequency of the high-frequency signal supplied to the ultrasonic wave generator by the signal generator, and changes the current. 5. The ultrasonic cleaning apparatus according to claim 1, wherein a frequency at which the current value detected by the voltage detecting means is detected is detected, the frequency is reset to a center frequency, and the sweep process is restarted. .

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